I have seen some really bad versions in older homes on TV and in MLS listings. We didn't even consider quite a few homes because they had basically ruined the house for us by opening up the kitchen and not considering the style/age of the home.
I think it would take someone with a great respect for the architecture of the home to do a thoughtful reno that looks like it belongs and doesn't scream reno. I have seen a few that were done well, with great care given to finishes and scale to blend with the rest of the house, but it seems like most of of the time they just wind up looking like someone cut open a wall.